English

Drawing the Horton Set in an Integer Grid of Minimum Size

Computational Geometry 2019-10-21 v1

Abstract

In 1978 Erd\H os asked if every sufficiently large set of points in general position in the plane contains the vertices of a convex kk-gon, with the additional property that no other point of the set lies in its interior. Shortly after, Horton provided a construction---which is now called the Horton set---with no such 77-gon. In this paper we show that the Horton set of nn points can be realized with integer coordinates of absolute value at most 12n12log(n/2)\frac{1}{2} n^{\frac{1}{2} \log (n/2)}. We also show that any set of points with integer coordinates combinatorially equivalent (with the same order type) to the Horton set, contains a point with a coordinate of absolute value at least cn124log(n/2)c \cdot n^{\frac{1}{24}\log (n/2)}, where cc is a positive constant.

Keywords

Cite

@article{arxiv.1506.05505,
  title  = {Drawing the Horton Set in an Integer Grid of Minimum Size},
  author = {Luis Barba and Frank Duque and Ruy Fabila-Monroy and Carlos Hidalgo-Toscano},
  journal= {arXiv preprint arXiv:1506.05505},
  year   = {2019}
}
R2 v1 2026-06-22T09:55:37.136Z